OP0172 LIMITED DIAGNOSTIC AND PROGNOSTIC VALUE OF RADIOGRAPHS OF HANDS AND FEET IN PATIENTS WITH UNDIFFERENTIATED ARTHRITIS SUSPECTED FOR RHEUMATOID ARTHRITIS: A RETROSPECTIVE COHORT STUDY
Authors: E. Ulijn, N. Den Broeder, D. Ten Cate, K. Van Overdijk, H. Demirel, R. B. M. Landewé, N. Van Herwaarden, A. Den Broeder
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Current recommendations suggest that the diagnostic workup of Undifferentiated Arthritis (UA) should include radiographs of hands and feet (x-HF) as presence of Rheumatoid Arthritis (RA) associated erosions might be of diagnostic and prognostic value. The diagnostic role of x-HF in RA is reflected in ACR/EULAR 2010 criteria, with erosions typical for RA allowing classification of RA even without fulfillment of the scoring system [1]. Additionally, early erosivity is one of the indicators of a poor RA prognosis [2]. RA seems to evolve into a milder disease at presentation, caused by a secular trend towards milder disease, or lead time effects (presenting earlier in disease course) [3]. Both trends would further decrease the prevalence of RA-associated erosions and thus utility of x-HF might have decreased both for diagnosis and identifying poor prognosis patients. <h3>Objectives</h3> To investigate the prevalence and diagnostic and prognostic value of RA-associated erosions on x-HF in a recent cohort of UA patients. <h3>Methods</h3> A retrospective cohort study in consenting UA patients visiting the rheumatology department at the Sint Maartenskliniek between 2012-2018 was done. UA suspected for RA was defined as 1/ current arthritis, 2/ Rheumatoid Factor (RF)/anti-Cyclic Citrullinated Peptide (anti-CCP) were tested, 3/ x-HF was made, 4/ RA was mentioned in the differential diagnosis. Radiological reports of x-HF were judged by experienced musculoskeletal radiologists, and all x-HF with an erosion mentioned in the report were reassessed by two experienced rheumatologists for typical RA-associated erosions. The prevalence of erosions was estimated, as well as whether RA classification (yes/no) or prognostic group (good/poor) were changed by erosivity. Subgroup-analyses were done for seronegative patients (non-elevated RF/anti-CCP) and patients without elevated Acute Phase Reactants (APR; i.e. ESR and CRP) as they might be expected to gain the most diagnostic and prognostic value from conducting x-HF. <h3>Results</h3> 724 patients were included in the analysis, of which 293 (40.5%) patients were eventually clinically diagnosed with RA during the time they were treated. There was a high agreement between 2010 ACR/EULAR classification criteria for RA and the clinical diagnosis reported by the treating rheumatologist (sensitivity of 79% and specificity of 89.6%). RA-associated erosions were found in 30 out of 724 included patients (4.1%, 2.9-5.9). Of the 437 seronegative patients, five (1.1%, 0.5-2.7) radiographs showed erosive disease. Eight out of 385 patients with non-elevated APR (2.1%, 1-4.1) had erosive disease. The x-HF resulted in a change to a positive RA classification in four out of 724 patients (0.5%, 0.2-1.2). X-HF erosivity changed the classification to prognostically unfavorable in five patients (0.6, 0.2-1.4), <i>Table 1</i>. In other words: these patients did not have RF or anti-CCP positivity, high disease activity (DAS28 &gt;5.1), but did have the prognostic factor 'early erosive disease'. <h3>Conclusion</h3> RA-associated erosions at presentation with UA are rare, and their presence rarely leads to a change in diagnosis or prognosis. Routine x-HF should therefore not be recommended in this context. X-HF made for any specific indication might of course be of value, and our results do not generalize to these cases. <h3>References</h3> [1] Van der Heijde D. et al. Ann Rheum Dis. 2013;72(4):479–81. [2] Visser H. et al. Rheum. 2002;46(2):357–65. [3] Diffin J.G. et al. J Rheumatol. 2014;41(8):1590–9. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.